In operating an information processing terminal, such as the laptop computer or the like, it is possible to carry out communication processing by connecting to an external communication network, such as a mobile communication network, by using a radio communication terminal having radio communication means. Such radio communication terminal, in use, is connected to an insertion opening, such as a USB (Universal Serial Bus) port, a card slot or the like, provided to the information processing terminal, and when not in use, can be removed from the insertion opening. There are conventional arts to prevent uncontrollable program runaway and system reset when the radio communication terminal is accidently removed from the information processing terminal in the course of the communication processing (Patent Documents 1, 2).